A pedestrian walks near the Bay Bridge on February 6, 2014, in San Francisco. California is getting a much-needed dose of rain and snow this weekend. / Justin Sullivan, Getty Images

by Doyle Rice and Gary Strauss , USA TODAY

by Doyle Rice and Gary Strauss , USA TODAY

The Pacific Northwest is expected to get up to another foot of snow Friday, Part II of a powerful storm that has already dumped more than 12 inches on areas s of Oregon and Washington.

The rare,back-to-back storms, which are pushing temperatures into the teens, have already caused a series of car crashes and massive traffic jams on Interstate 5, killing at least one person in Washington's Clark County. Another 25 vehicle pileup was reported on I-5 near Albany, OR.

Drought-plagued California is getting some much-needed precipitation, however, with some spots around the Bay Area picking up about an inch of rain Thursday and more storminess coming. Forecasters say a stronger system moving in Friday will dump as much as 6 inches of rain on Bay Area mountains and 2 feet of snow in the Sierra over the weekend.

"Any snowfall at this point is a very welcomed gift and surprise," said Steven Hemphill, communication manager for Sierra-at-Tahoe, a ski and snowboard resort in Twin Bridges, Calif.

Due to the lack of snow so far this winter, he said the resort is seeing 30% fewer visitors than usual, he said.

However, the moisture from the storms will make only a small dent in the huge precipitation deficits that have been racking up, according to AccuWeather meteorologist Anthony Sagliani.

"In many areas along the West Coast, anywhere from 18 to as much as 36 inches of rainfall is needed to bring an end to the drought, and that does not appear likely in the pattern," he said. But Sagliani said the rain and snow will bring some short-term benefits.

"If one could put a monetary value on the moisture from this storm, I speculate that it would easily be worth a billion dollars," according to Weather Underground meteorologist Jeff Masters, speaking about the impact of the rain on California's agricultural industry.

Thursday's U.S. Drought Monitor, a federal website that tracks drought, reported that around 10% of California was in "exceptional drought," the worst category.

The source of the storms is a phenomenon known as an atmospheric river, a plume of moisture from the tropics that fuels storms that bring heavy rain and snow to the West Coast. One name for the river is the "Pineapple Express," a plume that brings moisture-laden storms from the Pacific Ocean near Hawaii to California.

While the West deals with the welcome rain and snow, wintry weather will again be a nuisance to parts of the Midwest, Mid-Atlantic and Northeast. Though the storm will not be the blockbuster that some people had worried about, snow is still possible all the way from Iowa to Maine, and as far south as Virginia.

Thursday saw the lower 48 states record what is likely to be their lowest average temperature of the season, just 11 degrees.

Forecasters said the cold weather gripping the mid-Atlantic on Friday should remain in place through the weekend, and snow was possible.

Utility companies reported more than 325,000 customers without power in Pennsylvania, along with about 50,000 in Maryland. Officials have said they hope to have most of them back online by the end of the day Friday, but in some cases it may take much of the weekend.

PECO, the dominant electricity provider in the Philadelphia area, reports more than 288,000 customers out Friday morning in the five-county area. First Energy has about 27,550, almost all west of the city in York County, where there are also almost 4,000 PECO customers without power. And PPL reports 5,728 outages, most of them in Lancaster County, also west of Philadelphia.

Amtrak, meanwhile, says full service between Philadelphia and Harrisburg is being restored today after tracks have been cleared of fallen trees and debris, but riders may see delays of up to one-half hour.

According to AccuWeather.meteorologist Brian Wimer, "even with the weaker storms, there will still be snow to shovel, roads to treat and travel delays this weekend, centered on the Midwest and Northeast."